Q: Will a regular flu shot offer any protection against the H1N1 or swine flu virus?
A: In a word, no. Influenza viruses are notoriously shifty, changing their form each flu season in an effort to evade the human immune system. They do this by altering immune system-triggering features called antigens on the surface of the virus. That is why a new vaccine is developed each flu season. Vaccines work by exposing the immune system to deactivated virus particles, which tell the immune system how to defend against a particular virus.